Detection rules › Sigma

Unsigned Binary Loaded From Suspicious Location

Status
test
Severity
high
Log source
product windows, service security-mitigations
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects Code Integrity (CI) engine blocking processes from loading unsigned DLLs residing in suspicious locations

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Unsigned Binary Loaded From Suspicious Location
id: 8289bf8c-4aca-4f5a-9db3-dc3d7afe5c10
status: test
description: Detects Code Integrity (CI) engine blocking processes from loading unsigned DLLs residing in suspicious locations
references:
    - https://github.com/nasbench/EVTX-ETW-Resources/blob/45fd5be71a51aa518b1b36d4e1f36af498084e27/ETWEventsList/CSV/Windows11/21H2/W11_21H2_Pro_20220719_22000.795/Providers/Microsoft-Windows-Security-Mitigations.csv
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-03
modified: 2022-09-28
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    product: windows
    service: security-mitigations
detection:
    selection:
        EventID:
            - 11
            - 12
        ImageName|contains:
            - '\Users\Public\'
            - '\PerfLogs\'
            - '\Desktop\'
            - '\Downloads\'
            - '\AppData\Local\Temp\'
            - 'C:\Windows\TEMP\'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    EventID:
        - 11
        - 12
    ImageName|contains:
        - '\Users\Public\'
        - '\PerfLogs\'
        - '\Desktop\'
        - '\Downloads\'
        - '\AppData\Local\Temp\'
        - 'C:\Windows\TEMP\'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
ImageNamematch
  • C:\Windows\TEMP\ corpus 2 (sigma 2)
  • \AppData\Local\Temp\ corpus 11 (sigma 11)
  • \Desktop\ corpus 7 (sigma 7)
  • \Downloads\ corpus 10 (sigma 10)
  • \PerfLogs\ corpus 5 (sigma 5)
  • \Users\Public\ corpus 10 (sigma 10)